**Conflict of interest**

*Modern Applications of Electrostatics and Dielectrics*

transportation as shown in **Figure 20a**.

circuit, which can adjust to various situations.

with the counter pulses is shorter than that without the counter pulses. In the case of the bipolar intermittent pulse, the charge decay time is over six times longer than that of the continuously generated pulses. The ozone concentration produced by the corona discharges in the case of this method is 0.011 mg-O3/h and is lower than that with a conventional commercial frequency AC voltage, at 0.017 mg-O3/h. The results show that the efficiency of electrostatic elimination is much higher than conventional methods. With blown air **Figure 20b**, the charge decay time with the counter pulse is shorter than that without the counter pulses. The decrease of the amplitude and pulse width decreases the ion production and the efficiency of ion

*Charge decay time and the fluctuation width of the plate voltage as a function of the frequency of the* 

As shown in **Figures 12** and **18**, the same polarity ions as the applied voltage continuously flow into the plate at the same polarity phase, and the plate voltage increases according to the polarity. **Figure 21** shows the charge decay time and the fluctuation width of the plate voltage as a function of the frequency of the voltage phase. The fluctuation width is measured during the steady-state condition as shown in **Figure 10**. The charge decay time and the fluctuation width increase with decreasing frequency. Without blown air, the lower frequency is suitable for the electrostatic elimination; however, it causes a large fluctuation of the voltage potential on the objects. When the capacitance and the limitation of the voltage potential of the objects are low, suppressing the fluctuation of the voltage potential is required. The developed method can generate pulse voltages with wide-range frequencies ranging from several Hz to several kHz using the same transformer and

An intermittent pulse voltage AC power supply controlled by a PWM inverter with a small and lightweight transformer has been developed for highly efficient electrostatic elimination, and its specifications as an electrostatic eliminator have been highlighted. The PWM control can provide a flexible control of the frequency, pulse width, and amplitude of the voltage waveform applied to the corona discharge electrode. A certain degree of freedom in generating the pulse voltages and the waveforms can be optimized in various applications, which enables the design

**36**

**6. Conclusion**

**Figure 21.**

*voltage phase [26].*

The authors declare no conflict of interest.
